Counterbalance mechanism



Nov; 30 1926. v 1,608,720

R. L. CARTER COUNTERBALANCE MECHANISM Filed August 4, 1926' Patented Nov. 36, 1926.

UNITED STATES PATENT orrioei RAY L. CARTER, 0F PHOENIX, NEW YORK.

COUNTER/BALANCEMECHANISM;

Application filed August 4, 1926;

This invention relates "to a counter-balance mechanism, designed particularly for semi-portable appliances, such for example, as routing machines and thelike.

The object of the invention is to provide a bracket of novel construction and arrange ment adapted to be suspended from a ceiling or other over-head support, and being equipped with: a sheave. over which the counter-weight cable travels during the operation of the mechanism. A further object is to provide a lever which is pivoted to theibracket and is swingable in a vertical plane through an are less than 180, the free end of said lever being provided with means for attaching there-mote end of the counterweight cable, as well as the corresponding end of acable that supports the routing machine,- the said lever being equipped with means for limiting its upward swing. The arrangement of the bracket and: lever is such that, i a counter-balance of substantially lighter weight than the machine, over-balances the machine when the lever is swung to its uppermostlimit, and at the same time the gravitative pressure of the machine upon the work, when the lever is moved to its lowermost position, exceeds the normal discrepancyof the two bodies. This causes the positive' engagement of the machine with the vention will be understood from the detailed description which follows, and by reference to the accompanying drawing, in which:-

Figure 1 is a front side elevation ofthe complete mechanism; showing the counterbalanced objectheld in the elevated or r -w leased'positionbythe countenweightp Fig.

2 is a similar VlBWfShOWlDgthG routing machine lowered upon the work and overcoming the resistance of the weight; Fig. 3 is a rear side elevation of the bracket. And

Serial No. 127,1661

in Fig. 1. counter-acting the weight of portable and:

In the drawing,2 represents the over-head bracket, which is shown suspended from a ceiling or timber 3, the bracket, being pro vided with perforated flange 2, which may besecuredto the ceiling by bolts'2 The body of thebracket below the flangetapers downwardly and its lower end is perforated, to receive a bolt 4, by which one end of a lever 5 is pivoted and is adapted to beswu-ng in a vertical plane substantially parallel to the-front sideof the bracket. The free end of the lever 5 is provided witha transverse sloth, and intermediate its ends thelev'er is termed with a stop-h1g6, which is arranged to engage an edge of the bracket, for limiting the upwardswing of the lever (see Figs. 1 andw3), Near its upper end, the bracket is fitted with a sheave 6', which is pivoted by a pin 6, and over this sheave cable 7 travels. One end of t he cable 7 is secured to the loop 5 ofthc lever, the other end thereof being attached to --a counterweight, as 8 (see Fig. 2-). 9 represents con-- ventionally a router orotlier inotor driven machine, to which the counter-balance is ap plied, the machine being' ShOWH suspended from the loop-end of thelever 5, by means of a cable 9. In practice, the weight 'oithe counterbalance 8 is usually one-quarter to one-third less than the weight of the router or-other machine, which has been found to be sufiicient to positively and safely hold the' machinel 9 in the elevated or released position, when the angularity ofthe lever 5 is substantially as shown inFigA 1. This angle in the present case, has been so calcu' lated as to favor the relatively light counterweight, and enable it to over-balance the router, when the latter is elevated, and 'to positively hold the router against accidental: gravitation. To this 1 end, the stop a is located in such manner thatwhen the lever is swung upwardly it assumes the properangle (between 30 and40 to the'vertica l centerlsee' broken lineA Figs. 1 and 2) ,of the bracket 2.

To lower the machine 9to the work, as 10, the operator grasps" the handlesQ, and pulls downwardly with enough initial force to overcome thc resistance of the counterweight S; Thereafter, the force required to lower the router gradually lessons as the ma-- chine descends. After the lever passes the center indicated by the broken horizontal line w, the excess weight of the machine facilitates the descent, and when the router finally comes to rest upon the work 10, (see Fig. 2) the angle of the lever 5 is such as to favor the router and enable it to overcome the resistance of the Weight 8. W hen the lever 5 is in the position shown in Fig. 2, it sustains substantially the whole weight or thrust of the counter-balance, and leaves the router free to exert the greater portion of its full weight upon the work, which is desirable, for the reason that the operator may then suitably control the movements of the machine, thereby enabling him to accurately trace intricate and tortuous patterns, without danger of interference from the counter-weight.

By proportioning the counter-balance to the weight of the machine 9 substantially as herein set forth, and by constructing and arranging the lever 5 and limiting its upward and downward strokes, as shown and described, an operator of ordinary physical strength is able to maneuver the machine 9 during the performance of its work, as well as to raise and lower the same, with comparative ease and under perfect control. Furthermore, by arranging the counter-balance as explained, a router, or other machine, may be permanently mounted above a work-bench ready for instant use, and when not employed the router may be elevated to a sufficient height to insure the free use of the bench for other activities.

Obviously machines of greater, as well as lesser weight, than the router 9, may be supported by the bracket 2 and the lever 5 and the ratio of the counter-balance to the weight of the machines may be varied to suit such changes, or the ratio of the counter-balance to the dead weight of a machine may be increased or decreased over that herein set forth, by shifting the stop lug 5" in the proper direction, or by simply adding to or reducing the weight 8, without departing from my invention.

Having thus described my invention, what I claim is 1. In a counter-balance mechanism, a support, a lever having one end pivoted to the support and having its opposite end free to allow the free end of the lever to move above and below its pivoted end, means to support a machineior the like from the free end of the lever so as to dispose the machine on one side of the support, a counterbalance, and means to connect the counterbalance to the free end of the lever so as to dispose the counter-balance on the opposite side of the support.

2. In a counter-balance mechanism, a support, a lever device including a swinging arm pivoted to the support, means to support an article from the arm so as to dispose the article on one side of the support, a counter-balance, and means to connect the counter-balance to the arm so as to dispose same on the opposite side of the support.

3. The combination with a machine and a counter-balance therefor, of a bracket mounted upon an overhead support, a cable for supporting the machine, a cable for supporting the counter-balance, a member pivoted to the bracket and swingable in a vertical plane for raising and lowering the machine, the corresponding ends of said cables being attached to the said member, and means for limiting the effective swing of said lever to less than 180 and for preventing accidental raising and lowering of the machine.

l. A counter-balance mechanism adapted to be mounted on a. ceiling or other overhead support comprising a pending bracket, a

lever pivoted to the lower end of the bracket and swingable in a vertical plane through an arc of less than 180", means carried by the lever for limiting its upward stroke, the free end of the said lever being provided with means for attaching separate cables for supporting a counter-weight and a machine, and a sheave carried by the bracket over which one of the said cables travels.

5. The combination with a machine and a counter-balance of less weight than the machine, of a bracket adapted to be mounted upon a ceiling or other overhead support, separate cables for supporting the machine and counter-balance, a sheave pivoted to the bracket and supporting one of the said cables, a lever pivoted for movements in a vertical plane below the sheave, the free end of said lever connected to the corresponding ends of the cables, means for limiting the movements of the lever during the raising and lowering of the machine to less than 180, the angles of the said lever relatively to the vertical center of the bracket at the extremes of its strokes being such that the machine is held against accidental upward and downward movements.

6. The combination with a machine and a counter-balance therefor of a pending bracket adapted to be mounted upon a ceiling or other overhead support, a sheave pivoted to said bracket, a lever pivoted below said sheave and being swingable in a vertical plane towards and away from the sheave, the free end of said lever being formed with a loop and the medial portion of the lever being provided with means adapted to engage an edge of the bracket for limiting the upward stroke of the lever, a cable adapted to travel over said sheave, its ends being secured respectively to the counter-balance and to said loop, and a similar cable for suspending the machine from the loop-end of said lever.

- to enable the counter-balance 7. The combination with a machine and a counter-balance therefor, the said machine outweighing the counter-balance, of a bracket adapted to be mounted on a ceiling or other overhead support, a lever pivoted at one end to the bracket and being swingable in a vertical plane substantially parallel to the bracket, means for connecting the count er-balance and the machine to the free end of said lever, means for limiting the swing of the lever in the direction for elevating the machine and for disposing the lever at such an angle as to enable the lighter counterbalance to positively hold the machine against accidental gravitation, a sheave cooperating with the lever for supporting the counter-balance and the machine, said lever adapted to be swung downwardly manually and to be disposed at such an angle to the vertical center of the bracket as to neutralize the counter-balance while the machine is performing its work.

8. A counterbalance mechanism for routing machines and the like, comprising a pending bracket adapted to be secured to an overhead support, means pivoted to the bracket and swingable in a vertical plane for raising and lowering the counterbalance and the machine, a sheave carried by the bracket, a cable supported by said sheave and connecting the counterbalance and the machine with said swinging means, means for positioning the swinging means at the end of its upper stroke at such an angle as to over-balance and prevent the machine from accidental gravitation, said swinging member adapted to be manually operated for lowering the machine towards the work and to be disposed, at the end of its downward stroke, at such angle as to neutralize the counter-balance for enabling the machine to exert substantially its whole weight upon the work.

9. In acounter-balance mechanism, a support, a lever having one end pivoted to the support and having its opposite end free to allow the free end of the lever to move above and below its pivoted end, means to support a machine or the like from the free end of the lever so as to dispose the machine on one side of the support, a counterbalance, and means to connect the counter-balance to the free end of the lever so as to dispose the counter-balance on the opposite side of the support, and a stop on the lever engageable with the support to restrict movement of the lever.

10. In a counter-balance mechanism, a support, a lever device pivoted to the support, means to support an article from the device so as to dispose the article on one side of the support, a counterbalance, and means to connect the counter-balance to the device so as to dispose same on the opposite side of the support, and means to restrict movement of the device relative to the support,

11. In combination with a support, article carrying means, means to mount the article carrying means on the support for vertical movement, counterweight means, means to connect the counterweight means to the article carrying means, and means independent of the mounting means to limit movement of the article carrying means in one direction relative to the support.

In testimony whereof I afliX my signature.

RAY L. CARTER. 

